A system is known from the U.S. Pat. No. 5,694,026, for example, which discloses a turbine that is mechanically directly connected to a generator which, in turn, is connected via a converter and a transformer to a power supply grid. No mechanical gear is disposed between the generator and the turbine. The turbine is supplied with fuel during the operation in the generator mode, so that the generator is driven by the turbine and generates electrical power, which is then fed via the converter and the transformer into the power supply grid.
The generator functions as a motor for the start-up of the turbine from a standstill, wherein the electrical power in that case is supplied by the power supply grid, via the transformer and the converter, to the generator for starting the generator rotation and accelerating the turbine to the desired speed.